Industrial furnace



Patented Apr. 13, 1943 ziesso UNIT-ED smrss PATENT oFricE 'INDUSTRIAL FURNAC'E Lazenby C. Hamlink, Cleveland Heights, Ohio, assigncr to The Gas Machinery Company, Cleveland, Ohio, a corporation of Ohio Application May 26, 1941, Serial. NO. 395,123

2 Olaims.

The invention particularly relates to improvements in industrial furnaces of various types and is illustrated herein by a showing and description of a rotary forging furnace in which the improvements are incorporated.

A primary improvement of the instant invention consists in apparatus for adjusting the clearance area between the furnace wall structure and the rotating table so as to maintain efiicient functionng of this table clearance or its comparatively easy cleaning, if it becomes clogged. This improvementI is attained by a structure which permits a Vertical adjustment of the furnace wall whereby the cross-sectional area of the table clearance space can be Varied. Sloping side walls of the rotating table also as- `sist in maintaining efiicient table clearance. The Variation in the cross-sectional area of the clearance space between the table and the furnace Wall is obtained by a Vertical adjustment of the furnace wall relative to the table, the inner side of the furnace wall having a surface laterally spaced from and opposed to the outer side surface of the hearth, because of the relative arrangement of the opposed surfaces which, as shown in the accompanying drawing, are substantially parallel and sloped so that if projected they would be intersected by the axis (projected) of the rotatable table, and hence relative Vertical adjustment between the furnace wall and the table will vary the cross-sectional areaof the clearance space.

In several respects the instant invention presents improvements in the industrial furnaces patented in Harmon Patent No. 1,881,536. Particularly, the improvements presented in said Harmon patent and termed a syphon Vent therein are further improved upon in the instant invention so as to preserve the syphon vent principle in a simplified and more advantageous structure.

Still other of the instant improvements consist in securing the seal casing to the rotating table, preferably in a unitary structure, and in extending the seal exteriorly of the furnace Wall i.

structure to make the seal easily accessible for Cleaning.

Other and related improvernents of the instant invention will be apparent from the following description by reference to the accompanying z drawing.

The annexed drawing and the following description set forth in detail certain means illustrating the invention, such means disclosing, however, only one of the Various forms of assemblies in which the principles of the invention may be embodied.

In said annexed drawing:

Figure 1 is a Vertical section of a rotary forging furnace in which the instant invention is embodied, the section being taken in the plane indicated by theline l-l, Figure 2;

Figure 2 is a horizontal section, taken in the plane indicated by the line 2--2, Figure 1; and Figure 3 is a fragmentary Vertical section taken in the plane indicated by the line 3-3, Figure 2. p

Referring to the annexed drawing in which the same parts are indicated by the same respective numbers in the several Views, an oil or gas-fired rotary forging furnace l has an exterior side wall 2 combined with a dome 3 surrounding a hearth shown herein as a rotating table 4 to form a 'combustion chamber 5 between the dome and table, all as is well understood by those versed in the art. 'The table ll has clearance from the Wall '2 as indicated by the space 6. Through this space 6 the waste products from the combustion chamber 5 pass into upwardlydirected flues 1 formed in the Wall 2. The inlet ports 8 of the flues 1 are so located as to communicate with the space 6 at a level substantially below the hearth upper level indicated by the number 9, Figure 1. This location of the ports 8 is one of the improvements presented by the instant application and its advantages will be described hereinafter in detail.

The upper furnace wall and dome structure is mounted ona base support consisting of an annular water-cooled member Ill having a downWardly-extended leg Il which dips into a seal |2. This seal |2 includes an annular trough l3 surrounding and secured to the rotatable table 4, preferably being built integrally with the table, and, in the form of seal herein shown, is a water seal. This water seal also communicates with the clearance space 6. Since the seal trough E3 is supported by the rotatable table 4, instead of by the furnace wall structure, it can be and is extended outwardly of the furnace Wall and thus permits easy cleaning of the water trough |3 since its outer part is easily reached. This obviates the necessary work of removing the clean-out panels and draining the trough, When it is desired to clean the trough, and when the trough depends from and is supported by the furnace wall structure, as is true of present standard furnace Wall and seal trcugh structures. l

The main support for the side wall and dome structure and the rotatable table 4 is a subbase 14 formed I-beams, and welded to extended end portions l 'l of |these I-beams are the lower ends of a plurality of pairs of Vertical I-beams IB formed with vertically elongated slots |9 at their upper ends by means of which slots and bolts 20 the respective pairs of Vertical I-beams are held in proper relative alignment. These bolts 20 also intersect downwardly and outwardly extended portions IG' of housings IS which housing portions enclose the upper ends of the Vertical I- beams l8 upon which they are slideable, the inner edge portions of the housings IB being welded to the steel casing of the furnace wall 2. These housings IB have horizontal intermediate plate portions 162 to the upper surface of which, and somewhat spaced from the furnace wall 2, are welded nuts 2| which receive cooperating jack screws |5 mounted on the top of the respective pairs of Vertical I-beams |8. It will ,be evident then that the furnace side wall and dome structure can be vertically adjusted by means of the jack screws l5 and that thus the table clearance space 6 can be increased in cross-sectional area. This clearance adjustment permits the freeing of the space 8 of molten slag or foreign matter. The vertically elongated slots IS accommodate the movement of the housing-s IS relative to the vertical I-beams l8 and the bolts 20.

. Furthermore, the fact that the side wall 4' of the table 4 which defines one wall of the clearance space 6 has a surface which is sloping also assists in keeping the space 6 clear of slag and other obstructions. The feature Vof the invention relative to clearing the space 6 by means of the adjustment afforded by the jack screws {5 and by means of the sloping side wall 4' of the table 4 will be discussed hereinafter more in detail.

Other features of the improved furnace shown in the accompanying drawing, to which reference Will be here briefly made, and which are more or less standard, include the burners 22 for firing the furnace, the charge and discharge opening 23, the air curtain pipe 24, the water-cooled Shield 25, the seal overfiow pipe 28, and the drain 21, the lifting lug 28 for placing and removing the wall and dome structure, and the lifting lug 29 for manipulating the subbase and the unitary table and seal structure.

The considerable temperatures at which industrial furnaces are operated cause considerable molten scale to build up on the table 4 in the form of slag. This slag must be occasionally removed since otherwise it would run downward along the sides of the table and would cool and soli'dify. If it solidifies before it reaches the water trough 13, the rotating table 4 would be bound. The sloping surface of the side wall 4' of the table 4 facilitates the running off of the slag into the water trough 53. However, if the slag, or any other foreign matter or blets or other stock, lodges between the rotating table 4 and the furnace side wall 2, the clearance space 5 between the table 4 and the side wall 2 can be quickly radjusted through the medium of the jack screws IE. This adjustment requires only a few minutes* time; otherwise, if this clearance space 6 is fixed, several days' time would be required in order to cool the furnace down and make the desired repairs to the hearth brickwork and possibly also to the lower side wall brickwork. Thus, by means of the jack screw adjustment, the furnace Vcasing may be raised for any necessary adjustment of table clearance while the furnace is being operated.

The location of the ports 8 for the flues 1 substantially below the level of the top of the table 4 not only permits a Vertical adjustment of the furnace side wall and dome structure without unduly raising the ports 8 relative to the top of the table 4, but also assists in keeping the formed slag in molten condition until it reaches the sea] [2, since the slag is subject to waste gas heat for a considerable part of its passage through the space 6. i

The products of combustion do not rush out of the combustion chamber 5, but are held there until sufiicient pressure is built up in the furnace to force them out through the ports 8. This blanketing effect of the flue gases assists in producing a syphon effect through the ports 8 which withdraws infiltered air and water vapor through the flues 1. Also, when the fiue gases are forced out, the stack draft pulling upon them creates a suction effect in the upper part of the ports 8 which draws :any air which has infiltered into the lower pant of the space 6, as well as any vapor arising from the seal |2, into the outlet flues 1 and thus prevents the entrance of the infiltered air and the water vapor into the combustion chamber 5. Thus, the ports 8 act as syphon vents for infiltered air and water vapor. The result is that the furnace atmosphere is maintained constant, and scaling of the stock and surface decarburization t thereof are prevented. Also, preferably, the axes of the ports 8 are substantially perpendicular to the sloping surface of the side wall 4' of the table 4, a rela-tive assembly which assists in an efficient functioning of the syphon vents.

In addition to the benefits hereinbefore mentioned consequent upon the Vertical adjustability of the furnace structure and the sloping formation of the side wall 4' of the rotatable table 4, for increasing the area of the clearance space B and for keeping the latter free of obstructions, a further benefit arises from these improved features in that they compensate for table growth. The refractory material of which the body of the table 4 is formed expands under heat and oftentimes does not fully retract when cooled; hence, the increase in the size thereof which has been referred to as table growth."

Certain detail features for eifecting the rotation of the table 4 are shown in the accompanying drawing, land they are briefly referred to, being table supporting beams 38, an armular track 3| riding on the spaced turn-table rollers 32, a wo-rm and worm gear drive 33, and a centering pin structure 34.

What I claim is:

1. An industrial furnace having a Wall and dome structure, and 'a hearth spaced from the wall, said structure and hearth forming an enclosed combustion chamber, the wall being formed with outlet flues communicating with the space between the hearth and wall only through openings near the lower edge of the wall, and the combustion chamber communicating With said fiues through the upper portion of said space, whereby all combustion gases are caused to pass into said space and air infiltering into said space is diverted into said flues under the suction effect created in said flues by the passage of the combustion gases from said space into said fiues.

2. An industrial furnace having a Wall and dome structure, a hearth laterally spaced from the wall, the spaced opposed surfaces of the furnace wall and the hearth being sloped and substantially parallel, 'said structure and hearth forming an enclosed combustion chamber, the latter communicating with the space between the hearth and wall, the wall being formed with outlet flues having port portions communicating with said space only substantially below the upper level of the hearth, and the axes Iof said port portions being substantially perpendicular to said sloped surfaces, and means for relatively vertcally adjusting said structure and hearth.

LAZENBY C. HAMLINK. 

